Chip dropped this in Signal chat, I had a double watch of it.
I am an expert in PCR and qPCR (technique used to test for covid) and published the first mathematical model of it several years ago. I am a molecular biologist and trained in immunology as well. I checked this scientist’s credentials on PubMed, he is no quack. It is a good starting point for a serious discussion about vaccine passports. Yes, it’s long, sorry - you can save a few minuts at the beginning by skipping in, but the rest is worth it.